1 files changed, 70 insertions, 0 deletions
diff --git a/test/geometry/antipodalPoints.cpp b/test/geometry/antipodalPoints.cpp
new file mode 100644
index 0000000..d20dfb6
--- /dev/null
+++ b/test/geometry/antipodalPoints.cpp
@@ -0,0 +1,70 @@
+#include "../util.h"
+constexpr ll EPS = 0;
+#define double ll
+#define polar polar<ll>
+#include <geometry/formulas.cpp>
+#undef polar
+#undef double
+#include <geometry/antipodalPoints.cpp>
+#include "../geometry.h"
+
+vector<pair<int, int>> naive(vector<pt> ps) {
+	ll n = sz(ps);
+	auto test = [&](int i, int j){
+		if (dot(ps[j] - ps[i], ps[i - 1] - ps[i]) <= 0) return false;
+		if (dot(ps[j] - ps[i], ps[i + 1] - ps[i]) <= 0) return false;
+		return true;
+	};
+	ps.push_back(ps[0]);
+	ps.push_back(ps[1]);
+	vector<pair<int, int>> res;
+	for (ll i = 1; i <= n; i++) {
+		for (ll j = 1; j < i; j++) {
+			if (test(i, j) && test(j, i)) res.emplace_back(i % n, j % n);
+		}
+	}
+	return res;
+}
+
+void stress_test(ll range) {
+	ll queries = 0;
+	for (int tries = 0; tries < 100'000; tries++) {
+		int n = Random::integer<int>(3, 30);
+		auto ps = Random::convex(n, range);
+
+		auto got = antipodalPoints(ps);
+		for (auto& [a, b] : got) if (a > b) swap(a, b);
+		sort(all(got));
+
+		auto expected = naive(ps);
+		for (auto& [a, b] : expected) if (a > b) swap(a, b);
+
+		for (auto x : expected) {
+			auto it = lower_bound(all(got), x);
+			if (it == got.end() || *it != x) cerr << "error" << FAIL;
+		}
+		queries += n;
+	}
+	cerr << "tested random queries: " << queries << endl;
+}
+
+constexpr int N = 99'000;
+void performance_test() {
+	timer t;
+
+	auto ps = Random::convex(N, 1'000'000'000);
+
+	t.start();
+	auto got = antipodalPoints(ps);
+	t.stop();
+
+	hash_t hash = sz(got);
+	if (t.time > 50) cerr << "too slow: " << t.time << FAIL;
+	cerr << "tested performance: " << t.time << "ms (hash: " << hash << ")" << endl;
+}
+
+int main() {
+	stress_test(100);
+	stress_test(1'000'000'000);
+	performance_test();
+}